The present invention pertains to processes and apparatus for folding pants, and more particularly to processes and apparatus for making prefastened and refastenable pants.
Garments such as disposable absorbent garments have numerous applications including diapers, training pants, feminine care products, and adult incontinence products. The typical disposable absorbent garment is formed as a composite structure including an absorbent assembly disposed between a liquid permeable bodyside liner and a liquid impermeable outer cover. These components can be combined with other materials and features such as elastic materials and containment structures to form a product that is specifically suited to its intended purposes.
One form of disposable absorbent garment is a two-dimensional product that has open sides. Two-dimensional products, such as conventional diapers and some adult incontinence products, are generally flat and provided in an unfastened configuration. These garments have typically included fasteners such as adhesive tape fasteners or hook and loop type fasteners that releasably connect the front and back waist portions to secure the product about the wearer. Two-dimensional product can be easily applied or removed while the wearer is lying down.
Another form of disposable absorbent garment is a three-dimensional product with closed sides so that the product has a unitary waist opening and two leg openings. The wearer raises and lowers the garment to apply the product. Three-dimensional products are particularly appealing because the pant has a very garment-like look. Children for instance identify diaper products with babies, and most children do not like being identified with or as babies. Consequently, these children do not want to wear baby diapers, and instead prefer to wear training pants that look like adult underwear. Thus, the switch from a traditional diaper to a more garment-like or underwear-like training pant can be an important step in the toilet training process. Similarly, adults seeking the protection of incontinence products prefer the normalcy of a pant product rather than an incontinence product that must be applied in another fashion. Three-dimensional garments have been designed such that they can be torn to remove the garment from the wearer after it has been soiled.
Recently, prefastened and refastenable disposable absorbent garments have been proposed to provide the advantages of both two-dimensional and three-dimensional products. Prefastened and refastenable products can be applied and/or removed either like a conventional diaper or like a conventional training pant. For use as training pants, for example, there may be times when it would be useful to apply the product like a diaper. For instance, it might be more convenient to apply the product like a diaper when there is a desire not to remove the child""s shoes. Because it is difficult to know when a particular mode of applying the garment will be needed, it is beneficial to have a garment that is adaptable to being used either as a diaper or as a pant. This is preferable to keeping both types of garments available. A product that can be applied like either a diaper or a pant permits the interior of the product to be easily checked without having to pull the product downward.
Disposable absorbent products present many manufacturing challenges. In part, this is due to the high speed that is necessary to economically produce relatively low cost disposable absorbent products. Further, prefastened and refastenable garments present new challenges for high speed manufacturing. Such products must be folded in a manner that allows the refastenable fasteners to be properly aligned and engaged. Improperly attached or aligned fasteners can lead to many product deficiencies, including machine waste and/or delay, improper fit, fastener delamination during use, fastener disengagement during use, skin irritation, or the like.
Thus, what is lacking and needed in the art are improved processes and apparatus for folding pants, which processes and apparatus are suitable for use with discrete articles including mechanical fastening components and suitable for the manufacture of prefastened and refastenable pants.
In response to the above-referenced unfulfilled need in the art, new processes and apparatus for folding pants have been discovered. One aspect of the present invention pertains to a method of folding pants. One embodiment of the method comprises creating a folding nip between first and second transport devices, where the folding nip includes first and second vacuum rolls operatively associated with the respective first and second transport devices. Separation members are interposed between the first and second transport devices. The separation members are disposed on opposite sides of and outward from a machine center line. A plurality of discrete articles are transported to the folding nip. Each discrete article defines a leading half comprising opposed leading side panels, a trailing half comprising opposed trailing side panels, and an interconnecting region disposed between and interconnecting the leading and trailing halves. With the leading half positioned in proximity to the second vacuum roll and the trailing half positioned in proximity to the first vacuum roll, the interconnecting region is moved into the folding nip. The leading side panels are drawn toward the second vacuum roll and the trailing side panels are drawn toward the first vacuum roll. As the leading and trailing halves are advanced into the folding nip, the leading side panels are positioned on one side of the separation members and the trailing side panels are positioned on an opposite side of the separation members.
In another embodiment of the method, a plurality of discrete articles are transported to the folding nip formed between first and second transport devices and including first and second vacuum rolls. Each discrete article defines a leading half comprising opposed leading side panels, a trailing half comprising opposed trailing side panels, and an interconnecting region. The leading and trailing side panels are outstretched in a cross machine direction. The leading side panels comprise first fastening components, and the trailing half comprises second fastening components capable of refastenably engaging the first fastening components. The leading half and the outstretched leading side panels are positioned in proximity to the second vacuum roll, and the trailing half and the outstretched trailing side panels are positioned in proximity to the first vacuum roll. As the interconnecting region is moved into the folding nip, the outstretched leading side panels are drawn toward the second vacuum roll and the outstretched trailing side panels are drawn toward the first vacuum roll. The leading and trailing halves are advanced into the folding nip. The leading side panels are maintained separate from the trailing side panels while the interconnecting region is moved into the folding nip and until the discrete articles are downstream of the folding nip.
Another embodiment of the method of folding pants comprises: creating a folding nip between first and second transport devices, the folding nip comprising first and second nose rolls operatively associated with the respective first and second transport devices; interposing separation members between the first and second transport devices, the separation members disposed on opposite sides of a machine center line, the separation members disposed outward from the machine center line; transporting a plurality of discrete articles on the first transport device, each discrete article defining a leading half comprising opposed leading side panels, a trailing half comprising opposed trailing side panels, and an interconnecting region disposed between and interconnecting the leading and trailing halves, the leading and trailing side panels outstretched in a cross machine direction, the leading side panels comprising first fastening components, the trailing half comprising second fastening components capable of refastenably engaging the first fastening components; transporting the leading half past the folding nip; moving the interconnecting region into the folding nip; advancing the leading and trailing halves into the folding nip; and positioning the outstretched leading side panels on one side of the separation members and positioning the outstretched trailing side panels on an opposite side of the separation members.
Another aspect of the invention concerns an apparatus for folding pants having a leading half comprising opposed leading side panels, a trailing half comprising opposed trailing side panels, and an interconnecting region disposed between and interconnecting the leading and trailing halves. The apparatus comprises first and second transport devices defining therebetween a folding nip. The folding nip comprises first and second vacuum rolls operatively associated with the respective first and second transport devices. Separation members are interposed between the first and second transport devices, on opposite sides of and outward from a machine center line. The separation members each have an upstream end and an opposite downstream end. The upstream ends are located in proximity to the first and second vacuum rolls and the downstream ends are located downstream of the first and second vacuum rolls. A control system can be adapted to repeatedly activate and deactivate vacuum operation of the first and second vacuum rolls.
The present invention can be used with garments that include refastenable or non-refastenable seams. Non-refastenable bonded seams can be formed by ultrasonic bonds, adhesive bonds, thermal bonds, sewing, or the like. The present invention provides particular utility with garments that include refastenable seams. Fastening components to form refastenable seams can comprise separate elements bonded to another component of the pant. Alternatively, the fastening components can comprise a portion of another element of the pant, such as the bodyside liner, the outer cover, separate side panels if employed, integral side panels if employed, a belt-type component extending transversely across the chassis if employed, or the like. Thus, unless otherwise specified, the term xe2x80x9cfastening componentxe2x80x9d includes separate components which function as fasteners and regions of materials such as side panels, liners, outer covers or the like which function as fasteners. Moreover, a single material can define multiple fastening components to the extent that different regions of the material function as separate fasteners. The fastening components can be located on the side panels, between the side panels such as on the absorbent chassis, or a combination of the two. The fastening components can have any desired shape, such as square, rectangular, round, curved, oval, irregularly shaped, or the like. Each fastening component can comprise a single fastening element or multiple fastening elements.
The fastening components can comprise any refastenable fasteners suitable for absorbent articles, such as adhesive fasteners, cohesive fasteners, mechanical fasteners, or the like. In particular embodiments the fastening components comprise mechanical fastening elements for improved performance. Suitable mechanical fastening elements can be provided by interlocking geometric shaped materials, such as hooks, loops, bulbs, mushrooms, arrowheads, balls on stems, male and female mating components, buckles, snaps, or the like. In particular embodiments, the fastening components and mating fastening components comprise hook-and-loop fastening elements. One skilled in the art will recognize that the shape, density and polymer composition of the hooks and loops may be selected to obtain the desired level of securement between the fastening components and the mating fastening components. A more aggressive hook material may comprise a material with a greater average hook height, a greater percentage of directionally-aligned hooks, or a more aggressive hook shape.
Refastenable fastening systems allow for easy inspection of the interior of the pant-like product. If necessary, the fastening system also allows the pant to be removed quickly and easily. This is particularly beneficial when the pant contains messy excrement. For training pants, the caregiver can completely remove the pant-like product and replace it with a new one without having to remove the child""s shoes and clothing.
The present invention can be used in the manufacture of a wide variety of absorbent and non-absorbent products, including training pants, swim pants, diaper pants, incontinence garments, feminine care products, health care garments, apparel for institutional, industrial and consumer use, or other garments. Absorbent articles are adapted to be worn adjacent to the body of a wearer to absorb and contain various exudates discharged from the body. The absorbent articles can be prefastened to provide a pant-like product for the user. The product can then be pulled on like a conventional training pant, and subsequently checked or removed with the ease of a diaper-like product. Moreover, the product may be applied like a diaper rather than like a pant. Supplemental releasable fastening means such as frangible point bonds may be employed to maintain the absorbent article in a pant configuration until the user intentionally disengages the fasteners.
Particular training pants suitable for use with the present invention are disclosed in U.S. patent application Ser. No. 09/444,083, filed on Nov. 22, 1999 (corresponding to PCT application WO 00/37009 published Jun. 29, 2000) by A. Fletcher et al. and titled xe2x80x9cAbsorbent Articles With Refastenable Side Seams;xe2x80x9d which is incorporated herein by reference. This reference describes various materials and methods for constructing training pants. Training pants can also be constructed using the methods and apparatus disclosed in U.S. Pat. No. 4,940,464 issued Jul. 10, 1990 to Van Gompel et al.; and U.S. Pat. No. 5,766,389 issued Jun. 16, 1998 to Brandon et al.; which are also incorporated herein by reference.
Within the context of this specification, each term or phrase below will include the following meaning or meanings.
xe2x80x9cBondedxe2x80x9d refers to the joining, adhering, connecting, attaching, or the like, of two elements. Two elements will be considered to be bonded together when they are bonded directly to one another or indirectly to one another, such as when each is directly bonded to intermediate elements.
xe2x80x9cComprisingxe2x80x9d is inclusive or open-ended and does not exclude additional, unrecited elements or method steps.
xe2x80x9cConnectedxe2x80x9d refers to the joining, adhering, bonding, attaching, or the like, of two elements. Two elements will be considered to be connected together when they are connected directly to one another or indirectly to one another, such as when each is directly connected to intermediate elements.
xe2x80x9cDisposablexe2x80x9d refers to articles which are designed to be discarded after a limited use rather than being laundered or otherwise restored for reuse.
xe2x80x9cDisposed,xe2x80x9d xe2x80x9cdisposed on,xe2x80x9d and variations thereof are intended to mean that one element can be integral with another element, or that one element can be a separate structure bonded to or placed with or placed near another element.
xe2x80x9cElastic,xe2x80x9d xe2x80x9celasticizedxe2x80x9d and xe2x80x9celasticityxe2x80x9d mean that property of a material or composite by virtue of which it tends to recover its original size and shape after removal of a force causing a deformation.
xe2x80x9cElastomericxe2x80x9d refers to a material or composite which can be elongated by at least 25 percent of its relaxed length and which will recover, upon release of the applied force, at least 10 percent of its elongation. It is generally preferred that the elastomeric material or composite be capable of being elongated by at least 100 percent, more preferably by at least 300 percent, of its relaxed length and recover, upon release of an applied force, at least 50 percent of its elongation.
xe2x80x9cFabricsxe2x80x9d is used to refer to all of the woven, knitted and nonwoven fibrous webs.
xe2x80x9cFlexiblexe2x80x9d refers to materials which are compliant and which will readily conform to the general shape and contours of the wearer""s body.
xe2x80x9cForcexe2x80x9d includes a physical influence exerted by one body on another which produces acceleration of bodies that are free to move and deformation of bodies that are not free to move. Force is expressed in grams per unit area.
xe2x80x9cGraphicxe2x80x9d refers to any design, pattern, or the like that is visible on an absorbent article.
xe2x80x9cHydrophilicxe2x80x9d describes fibers or the surfaces of fibers which are wetted by the aqueous liquids in contact with the fibers. The degree of wetting of the materials can, in turn, be described in terms of the contact angles and the surface tensions of the liquids and materials involved. Equipment and techniques suitable for measuring the wettability of particular fiber materials or blends of fiber materials can be provided by a Cahn SFA-222 Surface Force Analyzer System, or a substantially equivalent system. When measured with this system, fibers having contact angles less than 90xc2x0 are designated xe2x80x9cwettablexe2x80x9d or hydrophilic, while fibers having contact angles greater than 90xc2x0 are designated xe2x80x9cnonwettablexe2x80x9d or hydrophobic.
xe2x80x9cIntegralxe2x80x9d is used to refer to various portions of a single unitary element rather than separate structures bonded to or placed with or placed near one another.
xe2x80x9cInwardxe2x80x9d and xe2x80x9coutwardxe2x80x9d refer to positions relative to the center of an absorbent article, and particularly transversely and/or longitudinally closer to or away from the longitudinal and transverse center of the absorbent article.
xe2x80x9cLayerxe2x80x9d when used in the singular can have the dual meaning of a single element or a plurality of elements.
xe2x80x9cLiquid impermeablexe2x80x9d, when used in describing a layer or multi-layer laminate, means that a liquid, such as urine, will not pass through the layer or laminate, under ordinary use conditions, in a direction generally perpendicular to the plane of the layer or laminate at the point of liquid contact. Liquid, or urine, may spread or be transported parallel to the plane of the liquid impermeable layer or laminate, but this is not considered to be within the meaning of xe2x80x9cliquid impermeablexe2x80x9d when used herein.
xe2x80x9cLongitudinalxe2x80x9d and xe2x80x9ctransversexe2x80x9d have their customary meaning. The longitudinal axis lies in the plane of the article and is generally parallel to a vertical plane that bisects a standing wearer into left and right body halves when the article is worn. The transverse axis lies in the plane of the article generally perpendicular to the longitudinal axis. The article as illustrated is longer in the longitudinal direction than in the transverse direction.
xe2x80x9cMemberxe2x80x9d when used in the singular can have the dual meaning of a single element or a plurality of elements.
xe2x80x9cNonwovenxe2x80x9d and xe2x80x9cnonwoven webxe2x80x9d refer to materials and webs of material which are formed without the aid of a textile weaving or knitting process.
xe2x80x9cOperatively joined,xe2x80x9d with reference to the attachment of an elastic member to another element, means that the elastic member when attached to or connected to the element, or treated with heat or chemicals, by stretching, or the like, gives the element elastic properties; and with reference to the attachment of a non-elastic member to another element, means that the member and element can be attached in any suitable manner that permits or allows them to perform the intended or described function of the joinder. The joining, attaching, connecting or the like can be either directly, such as joining either member directly to an element, or can be indirectly by means of another member disposed between the first member and the first element.
xe2x80x9cOuter cover graphicxe2x80x9d refers to a graphic that is directly visible upon inspection of the exterior surface of a garment, and for a refastenable garment is in reference to inspection of the exterior surface of the garment when the fastening system is engaged as it would be during use.
xe2x80x9cPermanently bondedxe2x80x9d refers to the joining, adhering, connecting, attaching, or the like, of two elements of an absorbent garment such that the elements tend to be and remain bonded during normal use conditions of the absorbent garment.
xe2x80x9cRefastenablexe2x80x9d refers to the property of two elements being capable of releasable attachment, separation, and subsequent releasable reattachment without substantial permanent deformation or rupture.
xe2x80x9cReleasably attached,xe2x80x9d xe2x80x9creleasably engagedxe2x80x9d and variations thereof refer to two elements being connected or connectable such that the elements tend to remain connected absent a separation force applied to one or both of the elements, and the elements being capable of separation without substantial permanent deformation or rupture. The required separation force is typically beyond that encountered while wearing the absorbent garment.
xe2x80x9cRupturexe2x80x9d means the breaking or tearing apart of a material; in tensile testing, the term refers to the total separation of a material into two parts either all at once or in stages, or the development of a hole in some materials.
xe2x80x9cStretch bondedxe2x80x9d refers to an elastic member being bonded to another member while the elastic member is extended at least about 25 percent of its relaxed length. Desirably, the term xe2x80x9cstretch bondedxe2x80x9d refers to the situation wherein the elastic member is extended at least about 100 percent, and more desirably at least about 300 percent, of its relaxed length when it is bonded to the other member.
xe2x80x9cStretch bonded laminatexe2x80x9d refers to a composite material having at least two layers in which one layer is a gatherable layer and the other layer is an elastic layer. The layers are joined together when the elastic layer is in an extended condition so that upon relaxing the layers, the gatherable layer is gathered.
xe2x80x9cSurfacexe2x80x9d includes any layer, film, woven, nonwoven, laminate, composite, or the like, whether pervious or impervious to air, gas, and/or liquids.
xe2x80x9cThermoplasticxe2x80x9d describes a material that softens when exposed to heat and which substantially returns to a nonsoftened condition when cooled to room temperature.
These terms may be defined with additional language in the remaining portions of the specification.